Valve timing control device of internal combustion engine

Abstract

To provide a valve timing control device of an internal combustion engine which can attain good lubrication performance for the interior of a speed reducer such as a first ball bearing.SOLUTION: A valve timing control device of an internal combustion engine is provided with: a sprocket 1 having a sprocket body 1a and a first annular restriction part 8; a following member 9 affixed to an end section of a camshaft 2; and first ball bearings 10 provided between an outer circumferential surface 9e of a disk-shaped body 9a of the following member and an inner circumferential surface 1e of the sprocket body. An opening 11 which opens in a camshaft direction is provided between a second annular restriction part 19 provided at the disk-shaped body and the first annular restriction part. A first recess 29 which is annular and faces the opening is provided on an outside surface of an outer circumferential section of the disk-shaped body, and the first recess is formed such that an outer circumferential section thereof opens to an inner circumferential surface of an inner ring 10a. A second recess 30 facing the opening is provided at an inner circumferential edge of the first annular restriction part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a valve timing control device for an internal combustion engine. [Background technology]

[0002] A known conventional valve timing control device for an internal combustion engine is described in the following Patent Document 1. This valve timing control device includes a sprocket to which rotational force from a crankshaft is transmitted, a driven member that is bolted to one end of a camshaft in the rotational axis direction and arranged relatively rotatably on the inner circumference of the sprocket, and a sliding bearing formed between the camshaft side of the inner circumference of the sprocket and the outer circumference of the driven member.

[0003] Depending on the engine condition, the rotational force of the electric motor is transmitted to the camshaft via a reduction gear, causing the camshaft to rotate relative to the sprocket via the sliding bearing, thereby changing the opening and closing timing of engine valves such as the intake valve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2021 / 085358A1 (Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional valve timing control device described in Patent Document 1, there was room for improvement in the lubrication of the sliding bearing. That is, because the cross-sectional area of ​​the annular opening formed between the adapter and the retaining plate on the back surface of the camshaft side of the driven member was small, lubricating oil scattered by the engine running was not sufficiently supplied to the sliding bearing.

[0006] The present invention has been devised in consideration of the above-mentioned conventional technical problems, and has as an object to provide a valve timing control device for an internal combustion engine that can ensure good lubrication for bearings that connect a driving rotor and a driven rotor. [Means for solving the problem]

[0007] In one preferred aspect, an opening that is open in the camshaft direction is provided between the driving rotor and the driven rotor, the driven rotor has an annular first recess whose outer surface on the camshaft side of the outer periphery of the disc portion faces the opening, and the outer periphery of the first recess opens to the inner periphery of the bearing portion. Effect of the Invention

[0008] According to a preferred embodiment of the present invention, good lubrication can be obtained for a bearing portion that bears between a driving rotor and a driven rotor. [Brief description of the drawings]

[0009] [Figure 1] 1 is a side view showing a vertical cross section of a reducer side of a valve timing control device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view showing the main components used in the present embodiment. [Diagram 3] FIG. 2 is an enlarged view of part A in FIG. [Figure 4] FIG. 2 is an enlarged perspective view of part A in FIG. [Diagram 5] FIG. 2 is a perspective view of a sprocket and a reducer viewed from the front plate side of the embodiment. [Figure 6] FIG. 2 is a view seen from direction B in FIG. [Figure 7] FIG. 2 is a perspective view of a sprocket used in the present embodiment. [Figure 8] FIG. 8 is an enlarged view of part C in FIG. [Figure 9] FIG. 2 is a perspective view of a driven member used in the present embodiment. [Figure 10]FIG. 6 is an enlarged view of a main portion of a second embodiment of the present invention. [Figure 11] FIG. 11 is an enlarged view of part D in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of a valve timing control device for an internal combustion engine according to the present invention will be described in detail with reference to the drawings. In this embodiment, the valve timing control device is applied to the intake side, but it is also possible to apply it to the exhaust side. [First embodiment] FIG. 1 is a side view showing a vertical cross section of the reducer side of a valve timing control device in a first embodiment of the present invention, FIG. 2 is an exploded perspective view showing the main components used in this embodiment, FIG. 3 is an enlarged view of portion A in FIG. 1, FIG. 4 is an enlarged perspective view of portion A in FIG. 1, FIG. 5 is a perspective view of the sprocket and reducer seen from the front plate side used in this embodiment, FIG. 6 is a view from direction B in FIG. 1, FIG. 7 is a perspective view of the sprocket used in this embodiment, and FIG. 8 is an enlarged view of portion C in FIG. 7.

[0011] As shown in Figures 1 and 2, the valve timing control device includes a timing sprocket 1 (hereinafter referred to as sprocket 1), which is a driving rotor, a camshaft 2 supported rotatably on a cylinder head 01 via a bearing bracket 02, and a phase change mechanism 3 disposed between the sprocket 1 and the camshaft 2 to change the relative rotational phase between the sprocket 1 and the camshaft 2 in accordance with the engine operating state.

[0012] As shown in Figures 1, 2 and 7, sprocket 1 is formed as an entire ring-shaped integral piece from sintered metal material obtained by sintering compacted metal powder, and has a ring-shaped sprocket body 1a, which is the main member formed with a substantially L-shaped cross section, and external teeth portion 1b, which is a gear portion, formed integrally on the outer periphery of sprocket body 1a.

[0013] Sprocket body 1a has six bosses 1c protruding from one end of its outer periphery facing camshaft 2 at intervals of approximately 60° in the circumferential direction. Each boss 1c has an arc-shaped outer surface and is internally formed with female threaded holes 1d into which the male threads of six bolts 7, described below, are screwed. By providing bosses 1c on the outer periphery, the overall outer diameter of sprocket body 1a excluding bosses 1c can be reduced without increasing the overall outer diameter, thereby making sprocket body 1a smaller and more lightweight.

[0014] Furthermore, sprocket body 1a has a large diameter hole formed in the center, and a first ball bearing 10 serving as a bearing is provided between the inner circumferential surface 1e of this large diameter hole and the outer circumferential surface 9e of driven member 9, which is a driven rotating body described below. This first ball bearing 10 supports the entire sprocket 1 so that it can rotate relatively to driven member 9. The specific configuration of first ball bearing 10 will be described later.

[0015] A rotational force is transmitted to each of the external teeth portions 1b from a timing chain (not shown) wound around a driven gear provided on a crankshaft of an internal combustion engine.

[0016] The inner peripheral surface 1e is formed such that its axial width W is longer than the axial width of the first ball bearing 10 (outer ring 10b).

[0017] In this embodiment, a timing chain is used as a means for transmitting rotational force to the external teeth portion 1b. However, the driven gear of the crankshaft may be directly meshed with the external teeth portion 1b having a modified structure to transmit the rotational force.

[0018] As shown in Figs. 1, 2, 7 and 8, the sprocket body 1a has an annular recess 6 formed in the front end face at one end side (front end side) in the rotation shaft direction.

[0019] The annular recess 6 is formed radially inward of the front end face of the sprocket body 1a, and has a flat bottom surface 6a and an annular inner circumferential surface 6b formed in the axial direction from the outer circumferential edge of the bottom surface 6a.

[0020] The bottom surface 6a has a depth that is approximately half the axial depth of the external teeth portion 1b. The annular inner peripheral surface 6b is formed so that its diametric length is slightly larger than the outer diameter of the sprocket body 1a.

[0021] An internal gear component 5 that constitutes a part of a reduction gear 13 (described later) is spigot-fitted (connected) to an annular inner peripheral surface 6b of the annular recess 6 from the rotation axis direction.

[0022] The internal gear component 5 is axially fitted into the annular recess 6 and is connected to the sprocket body 1a by bolts 7. The specific configuration of this internal gear component 5 will be described later. It is also possible to provide the sprocket body 1a and the internal gear component 5 as one unit, and use the entire unit as a driving rotor.

[0023] Furthermore, the sprocket body 1a is integrally provided with a first annular restricting portion 8, which is an annular protrusion that protrudes radially inward, on the other end (rear end) opposite the internal gear component 5 in the rotation axis direction.

[0024] The first annular restriction portion 8 constitutes part of the stopper mechanism, is formed integrally with the sprocket 1 when it is sintered, and is formed into an annular shape of a predetermined thickness from a sintered metal material. The first annular restriction portion 8 is formed into an annular shape extending radially inward from the rear end edge of the sprocket body 1a on the camshaft 2 side. The first annular restriction portion 8 is formed to have an outer diameter substantially the same as the outer diameter of the sprocket body 1a, and is disposed so that its annular inner surface on the internal gear component 5 side covers one end face of an outer ring 10b of a first ball bearing 10 (described later) on the camshaft 2 side.

[0025] As shown in Figs. 6 and 7, the first annular regulating portion 8 has two arc-shaped grooves 8b, 8c at predetermined positions on the inner circumferential surface 8a. The arc-shaped grooves 8b, 8c are provided at symmetrical positions of approximately 180° with respect to the center of the first annular regulating portion 8, and each arc length is formed in an angular range of approximately 120°. Between the arc-shaped grooves 8b, 8c on the inner circumferential surface 8a, that is, at approximately 180° positions in the circumferential direction, two first stopper protrusions 8d, 8e are provided. Each of the first stopper protrusions 8d, 8e is formed in an approximately arc shape, and each arc angle is formed at approximately 90°. As described later, each of the first stopper protrusions 8d, 8e is configured such that a second stopper protrusion 19a of one (one) of the second annular regulating portion 19 described later comes into contact with each edge facing each other in the circumferential direction from the circumferential direction to regulate the relative rotational position of the driven member 9.

[0026] Further, each female threaded hole 1d formed inside each boss portion 1c is formed to penetrate through to the camshaft 2 side and functions as a relief portion for the tip of the shaft portion 7a of the bolt 7 screwed inside. Each bolt 7 has a male thread formed on the outer circumferential surface of the shaft portion 7a, which screws into the female threaded hole 1d.

[0027] The camshaft 2 has two drive cams per cylinder on its outer periphery for opening and closing the intake valves (not shown). As shown in Fig. 1, the camshaft 2 is integrally provided with a flange 2b at one end 2a in the rotational axis direction, which positions the camshaft 2 in the axial direction via a bearing bracket 02.

[0028] The camshaft 2 has an insertion hole 2c formed along the internal axial direction from the tip surface of one end 2a. A shaft portion 14b of a cam bolt 14 (described later) is inserted into this insertion hole 2c, and a female thread portion 2d to which a male thread portion 14c of the cam bolt 14 is fastened is formed on a part of the inner peripheral surface on the tip side.

[0029] A front plate 15, which is a cover member, is provided on the front end surface of the internal gear component 5. As shown in Figures 1, 2 and 5, this front plate 15 is formed by, for example, stamping an iron-based metal plate into a disk shape by press forming, and has an outer peripheral portion 15a that is bolted to the front end surface of the internal gear component 5, a central portion 15b that is radially inward of the outer peripheral portion 15a and overlaps with a cage 24, which will be described later, in the axial direction, and an inner peripheral portion 15c that is radially inward of the central portion 15b and is offset and deformed in the axial direction toward the opposite side to the camshaft 2 than the central portion 15b.

[0030] Six bolt insertion holes 15d are formed through the outer circumferential portion 15a at equally spaced positions in the circumferential direction.

[0031] The central portion 15b is formed on the same plane as the outer peripheral portion 15a, and its inner surface on the camshaft 2 side faces one end face of an outer ring 22b of the second ball bearing 22 described later with a small gap therebetween, and is also positioned opposite the tip face of a cage portion 24b of the retainer 24 described later with a small gap therebetween.

[0032] The inner peripheral portion 15c is bent from the central portion 15b toward the opposite side to the camshaft 2 in a crank-like convex shape, and has a large-diameter through-hole 15e formed in the center.

[0033] At a position on the central portion 15b side of the outer peripheral portion 15a, an annular recess 26 is formed on the inner peripheral surface on the camshaft 2 side. This annular recess 26 is formed together with the front plate 15 when it is press-molded, and is formed by extruding it in the axially opposite direction from the camshaft 2. The annular recess 26 is formed so that its radial width is large enough to axially cover the tip end portion of a cage 24, which will be described later, and is formed with a substantially uniform width in the circumferential direction.

[0034] 1, 2 and 5, six grooves 27 are formed at approximately equal intervals (approximately 60° apart) on the outer periphery of the annular recess 26 in the circumferential direction of the front plate 15. The six grooves 27 are formed together with the annular recess 26 when the front plate 15 is press-molded, and have a mountain-shaped semicircular arc shape. In other words, each groove 27 is formed in a semicircular arc shape that protrudes radially outward (toward the outer circumferential surface) of the front plate 15.

[0035] Furthermore, a plurality of (six in this embodiment) lubricant oil drain holes 32 are formed through the bottom wall of the annular recess 26. Each of the lubricant oil drain holes 32 is formed at a position corresponding to the position where each of the recessed grooves 27 is formed, and each has a uniform inner diameter.

[0036] The six bolt insertion holes 15d provided in the outer circumferential portion 15a are adapted to receive the shaft portions 7a of the six bolts 7 that connect the front plate 15 to the internal gear component 5 and the sprocket body 1a via the internal gear component 5. The bolt insertion holes 15d are formed between adjacent grooves 27 in the circumferential direction of the outer circumferential portion 15a.

[0037] As shown in Figs. 1 and 2, the internal gear component 5 is provided separately from the sprocket body 1a, and is entirely formed as an annular integral part from a metal material having a relatively high hardness, such as steel. As shown in Fig. 1, the internal gear component 5 has a radial width L larger than the radial width of the bottom surface 6a of the annular recess 6, so that when the internal gear component 5 is fitted into the annular recess 6, the inner peripheral portion protrudes inward from the inner peripheral surface 4 of the sprocket body 1a. The axial width L1 is larger than the depth to the bottom surface 6a of the annular recess 6, so that when the internal gear component 5 is fitted into the annular recess 6, the end portion opposite the camshaft 2 in the axial direction protrudes axially forward from the annular inner peripheral surface 6b of the annular recess 6. The radial width L and axial width L1 of the internal gear component 5 ensure sufficient rigidity. In addition, the outer diameter of the internal gear component 5 (the outer diameter of the radial fitting surface 5c described later) is formed to be approximately the same as or slightly larger than the inner diameter d of the annular inner peripheral surface 6b of the annular recess 6.

[0038] The internal gear component 5 has a plurality of internal teeth 5a formed along the axial direction of its inner circumferential surface, an axial abutment surface 5b which is one side surface facing the camshaft 2 in the axial direction and abuts against the bottom surface 6a of the annular recess 6 from the axial direction, and a radial fitting surface 5c which is radially outside the axial abutment surface 5b and fits axially with the annular inner circumferential surface 6b of the annular recess 6.

[0039] Each of the internal teeth 5a is formed in a wavy shape on the entire inner peripheral surface, and each of the arc-shaped inner surfaces rotatably meshes with and holds a plurality of rollers 23, which are meshing members described later. The internal teeth 5a are subjected to a general heat treatment such as induction hardening after cutting the internal teeth 5a.

[0040] The axial contact surface 5b is formed as a flat restriction surface, and comes into close contact with the entire bottom surface 6a of the annular recess 6 when the internal gear component 5 is fitted into the annular recess 6 in the axial direction.

[0041] The radial fitting surface 5c is formed in a flat annular shape over its entire outer circumferential surface, and when the internal gear component 5 is fitted axially into the annular recess 6, it is fitted axially into the inner circumferential surface 6b of the annular recess 6 by intermediate fitting, which is a mechanical fit. However, the intermediate fit may be a press fit similar to an interference fit. Furthermore, the fit (including press fit) of the radial fitting surface 5c into the inner circumferential surface 6b of the annular recess 6 ensures coaxiality between the sprocket 1 and the internal gear component 5.

[0042] The internal gear component 5 has six bolt insertion holes 5e formed therethrough in the axial direction at positions corresponding to the female threaded holes 1d of the sprocket body 1a, into which the shaft portions 7a of the bolts 7 are inserted.

[0043] FIG. 9 is a perspective view of a driven member used in this embodiment.

[0044] 1, 2 and 9, the driven member 9 is formed separately from the cage 24 of the reducer 13. The driven member 9 is formed in a thick disk shape as a whole from sintered metal obtained by compressing and sintering metal powder. The driven member 9 has a disk-shaped main body 9a which is a disk portion, a cam bolt insertion hole 9b formed through the center of the disk-shaped main body 9a, and a second annular restricting portion 19 which is provided at the rear end portion of the disk-shaped main body 9a on the camshaft 2 side and which constitutes a stopper mechanism together with the first annular restricting portion 8.

[0045] The disc-shaped main body 9a has a circular fitting groove 9c formed on the inner circumferential side of the second annular restricting portion 19, i.e., on the inside surrounded by the second annular restricting portion 19, into which one end 2a of the camshaft 2 is fitted in the axial direction. The disc-shaped main body 9a also has a positioning pin hole 9d formed at a predetermined position on the bottom surface of the fitting groove 9c, into which a positioning pin (not shown) provided on the camshaft 2 is inserted. The disc-shaped main body 9a also has the above-mentioned first ball bearing 10 disposed between its outer circumferential surface 9e and the inner circumferential surface 1e of the sprocket main body 1a.

[0046] The cam bolt insertion hole 9b is configured so that the shaft portion 14b (intermediate shaft portion 14g) of the cam bolt 14 can be inserted with a small gap.

[0047] As shown in Fig. 2 and Fig. 9, the second annular restricting portion 19 is formed in a circular ring shape smaller than the outer diameter of the disk-shaped main body 9a, and is formed in a stepped shape with respect to the disk-shaped main body 9a. The second annular restricting portion 19 is integrally provided with a pair of second stopper protrusions 19a, 19b, which are protrusions protruding radially outward from the rotation center P, at predetermined positions on the outer circumferential surface. The second stopper protrusions 19a, 19b are provided at 180° symmetrical positions with respect to the rotation center P as an axis, and are disposed in the arc-shaped grooves 8b, 8c of the first annular restricting portion 8. The second stopper protrusions 19a, 19b have arc-shaped notched grooves formed on both side edges of their bases (roots) to reduce stress concentration.

[0048] When the driven member 9 rotates to the maximum relative rotation in the clockwise direction in Fig. 6 with respect to the sprocket 1, one circumferential edge of one second stopper protrusion 19a abuts against the opposing side edge of one first stopper protrusion 8d, mechanically restricting further relative rotation. When the driven member 9 rotates to the maximum relative rotation in the counterclockwise direction in Fig. 6, the other circumferential edge of one second stopper protrusion 19a abuts against the opposing side edge of the other first stopper protrusion 8e, mechanically restricting further relative rotation.

[0049] When the driven member 9 rotates rightward relative to the first stopper 8d as shown in Fig. 6 and one side edge of the second stopper protrusion 19a abuts against the opposing side edge of the first stopper protrusion 8d, the other second stopper protrusion 19b does not abut against the opposing side edge of the first stopper protrusion 8e with a predetermined gap. Also, when the driven member 9 rotates leftward relative to the first stopper 8d as shown in Fig. 6 and the other side edge of the second stopper protrusion 19a abuts against the opposing side edge of the first stopper protrusion 8e, the other second stopper protrusion 19b does not abut against the opposing side edge of the first stopper protrusion 8d with a predetermined gap.

[0050] 1, 3 and 6, a pair of openings 11 that are open to the camshaft 2 side are formed between the outer peripheral surface 19c of the second annular restricting portion 19 and the inner peripheral surface 8a of the first annular restricting portion 8 of the sprocket 1. The openings 11 are formed in arc-shaped recesses along the circumferential direction at two locations excluding the locations where the first stopper protrusions 8d, 8e of the first annular restricting portion 8 are formed.

[0051] 1 to 3 and 6, the first ball bearing 10 is disposed between the outer peripheral surface 9e of the disk-shaped main body 9a and the inner peripheral surface 1e of the sprocket body 1a, and has an inner ring 10a press-fitted and fixed onto the outer peripheral surface 9e of the disk-shaped main body 9a, an outer ring 10b press-fitted and fixed onto the inner peripheral surface 1e of the sprocket body 1a, and a plurality of balls 10c rollably disposed between the inner and outer rings 10a, 10b via a cage 10d. The inner ring 10a, balls 10c, and cage 10d of the first ball bearing 10 face the opening 11 from the axial direction.

[0052] The inner ring 10a is formed such that its length in the rotational axis direction is longer than the axial width of the outer circumferential surface 9e of the disk-shaped main body 9a, and one end face in the rotational axis direction facing the camshaft 2 is positioned in the axial direction by the inner surfaces of the second stopper protrusions 19a, 19b. The other end face in the rotational axis direction is positioned in the axial direction by a flat outer surface 24d on the camshaft 2 side of the outer circumferential part of a cage 24, which will be described later.

[0053] One end face of the outer ring 10b facing the camshaft 2 in the direction of the rotational axis is positioned in the axial direction by the inner surface 8f of the first annular regulating portion 8, and the other end face is positioned in the axial direction by one side surface of the internal gear component 5 facing the camshaft 2 via an annular spacer 28.

[0054] 1, the annular spacer 28 has its outer peripheral surface fitted and held on the inner peripheral surface 1e of the sprocket body 1a, and is disposed in axial contact between one axial end face of the internal gear component 5 and one end face of the outer ring 10b of the first ball bearing 10. As a result, the outer ring 10b is positioned in the axial direction by the internal gear component 5 and the inner surface 8f of the first annular restricting portion 8 via the annular spacer 28.

[0055] Alternatively, instead of this annular spacer 28, it is also possible to provide an annular protrusion having the same axial length and the same inner and outer diameters as the annular spacer 28 integrally on the inner peripheral edge of the inner surface of the internal gear component 5 facing the driven member 9.

[0056] A first recess 29 is formed on one side surface of the outer periphery of the disk-shaped main body 9a on the side of the first annular restricting portion 8. This first recess 29 is formed in the shape of an arc groove along the circumferential direction on one radially outer side surface of the second annular restricting portion 19, and on two portions excluding the second stopper protrusions 19a, 19b. This first recess 29 faces the above-mentioned opening 11 and is in communication with this opening 11, and its outer periphery faces the outer periphery surface of the inner ring 10a of the first ball bearing 10.

[0057] The driven member 9 is adapted to be fastened axially to one end 2a of the camshaft 2 together with the retainer 24 by the cam bolt 14, with one end 2a of the camshaft 2 being fitted axially into the fitting groove 9c.

[0058] Returning to the previous section, as shown in Figures 1, 3, 4, 7 and 8, the first annular restricting portion 8 of the sprocket body 1a is formed with a second recess 30 on the inner edge of the inner circumferential surface 8a facing the driven member 9. This second recess 30 is formed by cutting out the inner edge of the inner circumferential surface 8a in an annular shape along the circumferential direction, and is formed with a substantially arc-shaped cross section. The second recess 30, together with the first recess 29, faces the opening 11, and opens toward the space between the inner ring 10a and outer ring 10b of the first ball bearing 10, specifically, between the outer ring 10b and each ball 10c.

[0059] As shown in Figures 1 and 2, the cam bolt 14 has a substantially cylindrical head 14a, a shaft portion 14b fixed integrally to the head 14a, and a male thread portion 14c formed on the outer peripheral surface of the shaft portion 14b and screwed into the female thread portion 2d of the camshaft 2.

[0060] The head 14a has a hexagonal tool hole 14d formed at the tip thereof into which a tool such as a hexagonal wrench is inserted. The entire outer circumferential surface of the head 14a is subjected to heat treatment such as induction hardening, making the head 14a harder than other portions.

[0061] Furthermore, each needle roller 25a of the needle bearing 25 is supported for rolling on the high hardness outer peripheral surface of the head 14a. The seat surface 14f is adapted to seat on an opposing surface on the outer side of the edge of a bolt hole 24c formed on the inner peripheral part of the retainer 24 when the male thread portion 14c of the cam bolt 14 is screwed into the female thread portion 2d of the camshaft 2 and fastened.

[0062] A large-diameter intermediate shaft portion 14g is integrally provided at the base of the shaft portion 14b and the head portion 14a, that is, at the center of the axial seating surface 14f of the head portion 14a.

[0063] As shown in Figures 1 and 2, the phase change mechanism 3 is mainly composed of an electric motor 12 arranged on the front end side of the sprocket 1, and a reducer 13 that reduces the rotational speed transmitted from the electric motor 12 via the Oldham coupling and transmits it to the camshaft 2.

[0064] The electric motor 12 is a so-called brushless DC motor and has a cylindrical motor housing 16 with a bottom that is fixed to a chain case not shown, a motor stator not shown that is provided on the inner surface of the motor housing 16 and has coils and the like housed inside, a motor shaft 17 arranged on the inner side of the coil, a permanent magnet not shown that is fixed to the outer periphery of the motor shaft 17, and a control unit 18 provided at the front end of the motor housing 16 opposite the sprocket 1.

[0065] The motor housing 16 is formed in a substantially cup shape, and a through hole into which the motor shaft 17 is inserted is formed in the approximate center of the front end (bottom wall). Meanwhile, a flange portion 16a that protrudes radially outward is integrally formed on the outer periphery of the rear end. Three bracket pieces 16b are integrally formed on this flange portion 16a at positions of approximately 120° in the circumferential direction. In addition, bolt insertion holes 16c are formed through each of the three bracket pieces 16b, through which bolts are inserted for connecting to a chain case (not shown).

[0066] Furthermore, three different bolt insertion holes, through which three bolts 34 are inserted, are formed between each pair of bracket pieces 16b in the circumferential direction of the flange portion 16a. Each bolt 34 is adapted to connect the control unit 18 to the motor housing 16. It is possible to further increase the number of bracket pieces 16b and bolt insertion holes 16c.

[0067] The motor stator is formed as a single unit mainly from a resin portion made of a synthetic resin material, and a coil is fixed inside by molding.

[0068] The motor shaft 17 is made of a metal material and has a cylindrical shape, and has a two-sided width portion (not shown) formed along the tangential direction on the outer surface of the tip portion 17a on the side of the reducer 13. A pair of fitting grooves cut out in a direction perpendicular to the two-sided width portion are formed on the tip edge side of the tip portion 17a. Stopper members (not shown) that restrict the movement of the intermediate member 31 (described later) toward the cam bolt 14 are fitted and fixed radially into both fitting grooves.

[0069] Further, the motor shaft 17 has a tip end 17a disposed adjacent to the head 14a of the cam bolt 14 with a small gap in the rotational axis direction. Further, the entire tip end 17a, including the stopper member, can be inserted axially into the tool hole 14d.

[0070] The stopper member is formed in a C-ring shape and is capable of elastically deforming in a radially expanding direction and a radially contracting direction by its own elastic force.

[0071] The control unit 18 has a housing 18a formed in a box shape from a synthetic resin material. Inside this housing 18a, a current-carrying circuit such as a bus bar that supplies power to the electric motor 12, a rotation sensor that detects the rotational position of the motor shaft 17, a circuit board that controls the amount of current, etc. are accommodated and arranged. In addition, the control unit 18 has a power supply connector 18b that is electrically connected to the current-carrying circuit and a signal connector (not shown) that are integrally provided in the housing 18a.

[0072] The power supply connector 18b has a terminal protruding inward and connected to a battery (power source) via a female terminal of a control unit (not shown). On the other hand, the signal connector has a built-in terminal connected to the control unit via a female terminal, and outputs a rotation angle signal detected by the rotation sensor to the control unit.

[0073] An intermediate member 31 is provided at the tip end 17a of the motor shaft 17. This intermediate member 31 constitutes a part of an Oldham coupling, which is a joint connected to the reduction gear 13, and has a cylindrical base 31a fixed to the tip end 17a of the motor shaft 17, as shown in Figures 1 and 2. This cylindrical base 31a has a pair of two-face flat portions on both sides of its circular outer surface, i.e., at 180° positions in the circumferential direction, so that the outer shape is formed into a substantially elliptical shape.

[0074] Further, a through hole into which the tip portion 17a of the motor shaft 17 is inserted is formed at the center position of the cylindrical base portion 31a.

[0075] The through hole has a pair of opposing surfaces, each having a two-sided width, formed on a circular inner peripheral surface along the radial direction from the rotation axis of the motor shaft 17. This results in an elliptical shape that is elongated in the radial direction and similar to the outer shape of the cylindrical base portion 31a. Therefore, the intermediate member 31 is movable in the radial direction relative to the tip end portion 17a of the motor shaft 17 through the elliptical through hole.

[0076] Two transmission keys 33a, 33b, which are a pair of protruding parts, are integrally provided at approximately the center of the pair of flat parts in the longitudinal direction. Each of the transmission keys 33a, 33b is formed in a substantially rectangular plate shape and protrudes radially outward from the two flat parts of the cylindrical base 31a.

[0077] The reducer 13 is provided separately from the electric motor 12 in the axial direction, and each of the components is housed and disposed between the driven member 9 and the front plate 15. That is, as shown in Figures 1 and 2, the reducer 13 is mainly composed of a cylindrical eccentric shaft member 21 which is an input shaft with a portion disposed inside the sprocket body 1a, a second ball bearing 22 fixed to the outer periphery of the eccentric shaft member 21, a plurality of rollers 23 provided on the outer periphery of the second ball bearing 22 and held so as to be able to roll in each of the internal teeth 5a of the internal gear component member 5, and a cage 24 provided on the side of the disk-shaped groove portion 9g of the driven member 9 and which holds the plurality of rollers 23 in the rolling direction while allowing them to move in the radial direction.

[0078] The eccentric shaft member 21 has an eccentric camshaft 21a arranged on the outer periphery of a needle bearing 25 provided on the outer periphery of the head 14a of the cam bolt 14, and a large-diameter cylindrical portion 21b which is a connecting portion on the electric motor 12 side of the eccentric camshaft 21a.

[0079] The eccentric camshaft 21a is formed in a cylindrical shape with an axial length slightly longer than the axial length of the needle bearing 25. The eccentric camshaft 21a has a wall thickness t that varies in the circumferential direction, and the axis X of the eccentric camshaft 21a is slightly eccentric with respect to the axis Y of the motor shaft 17 of the electric motor 12 (see FIG. 1).

[0080] The cylindrical portion 21b is formed in a substantially circular shape with a uniform thickness and is slightly thicker than the eccentric camshaft 21a. The cylindrical portion 21b protrudes from inside the sprocket body 1a toward the electric motor 12 through the through hole 15e of the front plate 15. The cylindrical portion 21b and the intermediate member 31 form an Oldham coupling.

[0081] That is, the cylindrical portion 21b has a two-face width fitting hole 21d formed therein, into which the cylindrical base portion 31a of the intermediate member 31 can be fitted from the axial direction. A pair of crescent-shaped convex portions (not shown) constituting the two-face width are provided at positions of approximately 180° in the circumferential direction on the inner peripheral surface of the fitting hole 21d. In addition, a pair of key grooves 21c, 21c into which the two transmission keys 33a, 33b of the cylindrical base portion 31a can be fitted from the rotation axis direction are formed at approximately the center positions of the pair of convex portions in the vertical direction in FIG. Each of the key grooves 21c, 21c is formed in a rectangular shape similar to each of the transmission keys 33a, 33b, and its depth is set to be approximately the same length as the width of each of the transmission keys 33a, 33b.

[0082] The needle bearing 25 has a plurality of needle rollers 25a that roll on the outer peripheral surface 14e of the head 14a of the cam bolt 14, and a cylindrical shell 25b that is fixed to a stepped surface formed on the inner peripheral surface of the eccentric camshaft 21a and has a plurality of grooves on its inner peripheral surface that rotatably hold the needle rollers 25a.

[0083] 1 and 2, the second ball bearing 22 is disposed so as to almost entirely overlap the needle bearing 25 at a radial position thereof. The second ball bearing 22 is composed of an inner ring 22a, an outer ring 22b, a plurality of balls 22c disposed between the inner and outer rings 22a and 22b, and a cage 22d that holds the balls 22c.

[0084] The inner ring 22a is press-fitted and fixed to the outer peripheral surface of the eccentric camshaft 21a, whereas the outer ring 22b is free and not fixed in the axial direction. That is, one end face of the outer ring 22b on the electric motor 12 side in the axial direction is in a non-contact state with the inner surface of the inner peripheral portion 15c of the front plate 15 via a small gap C1. The other end face of the outer ring 22b in the axial direction is also in a non-contact state with the opposing inner surface 24e (described later) of the cage 24 via a small gap. As a result, one end face of the outer ring 22b in the axial direction is restricted from moving in one axial direction by the inner peripheral portion 15c, and the other end face in the axial direction is restricted from moving excessively in the other axial direction by the inner surface 24e.

[0085] The rollers 23 rollably abut against the outer peripheral surface of the outer ring 22b. A crescent-shaped clearance (not shown) is formed between the outer peripheral surface of the outer ring 22b and the outer surfaces of the rollers 23 of the cage 24. Therefore, the second ball bearing 22 as a whole is capable of eccentric movement in the radial direction via the clearance in association with the eccentric rotation of the eccentric camshaft 21a.

[0086] The cage 24 is formed into a substantially disk-like shape by press molding a metal plate, and is disposed in contact with the front end side of the disk-shaped groove portion 9g side of the driven member 9. That is, the cage 24 has a disk-shaped base portion 24a that axially contacts the bottom surface of the disk-shaped groove portion 9g of the disk-shaped main body 9a of the driven member 9, and a cage portion 24b that is integrally provided on the outer periphery of the base portion 24a and holds the multiple rollers 23 that are meshing members. The cage 24 is made harder than the driven member 9 by, for example, induction hardening after the entire cage 24 is press molded.

[0087] The base 24a has a bolt hole 24c formed in the center through which the shaft 14b of the cam bolt 14 is inserted, and the outer periphery is bent approximately in a crank shape, with an outer surface 24d and an inner surface 24e of this outer periphery being slightly offset from each other in the radial direction and formed flat.

[0088] 3, outer surface 24d of the outer periphery abuts against the other axial end face of inner ring 10a of first ball bearing 10 for axial positioning. Meanwhile, inner surface 24e of the outer periphery abuts against one axial end face of outer ring 22a of second ball bearing 22 for axial positioning. Therefore, outer surface 24d and inner surface 24e function as axial positioning parts for first and second ball bearings 10, 22.

[0089] Further, the base portion 24a has a pin insertion hole through which a positioning pin (not shown) for positioning the driven member 9 at a predetermined position is inserted.

[0090] The cage portion 24b is formed in a circular ring shape extending from the outer peripheral edge of the outer periphery of the base portion 24a toward the electric motor 12 side, and a plurality of retaining holes 24h for holding each roller 23 are formed radially through at equally spaced positions in the circumferential direction.

[0091] Each of the retaining holes 24h is formed as an elongated rectangular hole extending from the base end edge of the cage portion 24b on the deformed portion 24d side toward the tip end edge, and the tip end side is closed. The rollers 23 are rotatably held inside the retaining holes 24h, and the total number of the rollers 23 is smaller than the total number of the internal teeth 5a of the internal gear component 5, thereby obtaining a predetermined reduction ratio.

[0092] Each roller 23 is made of an iron-based metal, and moves radially in accordance with the eccentric movement of the second ball bearing 22 while being fitted (meshed) with each internal tooth 5a of the internal gear component 5. Each roller 23 is adapted to oscillate radially while being guided in the circumferential direction by both axial side edges of each retaining hole 24h.

[0093] Further, each roller 23 is arranged so as to be able to roll only on the internal teeth 5a of the internal gear component 5 within the range of the axial length of the retaining hole 24h among the internal teeth 5a of the internal gear component 5.

[0094] 1, the cage 24 (cage portion 24b) is formed so that its outer diameter is smaller than the outer diameter of the journal portion 41 of the driven member 9. When the cage 24 is axially assembled to the driven member 9, the outer peripheral edge of the cage portion 24b on the driven member 9 side abuts against the inner peripheral edge of the journal portion 41 in the axial direction.

[0095] The control unit detects the current engine operating state based on information signals from various sensors such as a crank angle sensor, an air flow meter, a water temperature sensor, an accelerator opening sensor, etc. (not shown), and controls the engine based on this. The control unit also controls the rotation of motor shaft 17 by energizing the coil of electric motor 12 based on the information signals and the rotational position detection mechanism, and controls the relative rotational phase of camshaft 2 with respect to timing sprocket 1 by reducer 13. [Effects of this embodiment] The operation of the valve timing control device in this embodiment will be briefly described below. First, when the sprocket 1 rotates via the timing chain in accordance with the rotational drive of the crankshaft of the engine, this rotational force is transmitted to the internal gear component 5. The rotational force of this internal gear component 5 is transmitted from each roller 23 via the cage 24 and the driven member 9 to the camshaft 2. As a result, the drive cam of the camshaft 2 opens and closes each intake valve.

[0096] During a predetermined engine operation after the engine has been started, a control current from the control unit is applied to the coil of the electric motor 12 to rotate the motor shaft 17 in the forward and reverse directions. The torque of the motor shaft 17 is transmitted to the eccentric shaft member 21 via the Oldham coupling, and the reduced torque is transmitted to the camshaft 2 by the operation of the reducer 13.

[0097] As a result, the camshaft 2 rotates forward and backward relative to the timing sprocket 1, converting the relative rotation phase. Therefore, the opening and closing timing of each intake valve is converted to the advance or retard side.

[0098] In this way, the opening and closing timing of the intake valve is continuously changed to the advance side or the retard side, thereby improving engine performance such as engine fuel efficiency and output.

[0099] In this embodiment, the lubricating oil O scattered to the outside as the engine is driven is effectively collected in the first recess 29 from the opening 11 between the sprocket 1 and the driven member 9, as shown by the arrow in FIG. 3. The first recess 29 is shaped to be concave in the axial direction, which attenuates the momentum of the scattered lubricating oil O and more effectively collects it. The lubricating oil O that has entered the first recess 29 is caused to flow toward the first ball bearing 10 on the outer periphery by the rotational centrifugal force of the sprocket 1 and the like, and efficiently lubricates the first ball bearing 10. The lubricating oil O that has entered the first recess 29 from the opening 11 flows into the second recess 30 due to the rotational centrifugal force, and is further forcibly supplied to the inside of the first ball bearing 10.

[0100] In particular, since the radially outer opening end of first recess 29 is the inner circumferential surface of inner ring 10a of first ball bearing 10, lubricating oil O that flows into the inside of first recess 29 flows from the outer circumferential surface of inner ring 10a toward outer ring 10b, effectively lubricating these, and also flows into spaces between each ball 10c and cage 10d, effectively lubricating the entire first ball bearing 10.

[0101] Furthermore, the lubricating oil O that has lubricated the first ball bearing 10 passes between the outer circumferential side retainer 24 and the rollers 23 and the internal teeth 5a, and so on, to sufficiently lubricate these spaces.

[0102] The opening 11 is formed in a wide annular shape between the inner circumferential surface 8a of the first annular restricting portion 8 and the outer circumferential surface 19c of the second annular restricting portion 19, and has a large opening area, which increases the efficiency of collection into the first recess 29. As a result, a large amount of lubricating oil O can be supplied from the first recess 29 toward the first ball bearing 10. This improves the lubricating performance for the first ball bearing 10 and the cage 24.

[0103] The lubricating oil that has flowed into the cage 24 is also supplied to the inner ring 22a, the outer ring 22b and the balls 22c of the second ball bearing 22, and serves to lubricate these as well.

[0104] Furthermore, in this embodiment, as described above, the lubricating oil O that has lubricated the first ball bearing 10, the second ball bearing 22, and the spaces between the internal teeth 5a and the rollers 23 and the retaining hole 24h can be quickly discharged to the outside from each lubricating oil discharge hole 32. In other words, the lubricating oil supplied from the opening 11 to the first recess 29 and the second recess 30 can be quickly discharged to the outside from each lubricating oil discharge hole 32 without remaining in the reducer 13 after lubricating the first and second ball bearings 10, 22, etc.

[0105] Therefore, for example, when starting the internal combustion engine, it is possible to suppress the occurrence of a technical problem such as a decrease in the mechanical drive speed of the valve timing control device due to the viscous resistance of the lubricating oil.

[0106] In particular, each lubricant oil discharge hole 32 is provided radially outward from the outer ring 22a of the second ball bearing 22. For this reason, the lubricant oil supplied into the reducer 13 does not accumulate here while lubricating the second ball bearing 22 and the like due to centrifugal force during driving, but moves directly outward and is discharged to the outside from each lubricant oil discharge hole 32. Therefore, the second ball bearing 22 is prevented from generating driving resistance due to the viscous resistance of the lubricant oil.

[0107] Furthermore, in this embodiment, the inner and outer surfaces 24d, 24e of the outer periphery of the base 24a of the retainer 24 are flat, making it possible to control the dimensions and to precisely position the first and second ball bearings 10, 22 in the axial direction.

[0108] In the first ball bearing 10, one axial end face of the inner ring 10a is disposed opposite the inner surface of the second stopper protrusions 19a, 19b of the driven member 9 (second annular restricting portion 19), while the other axial end face of the inner ring 10a is disposed opposite the outer surface 24d of the outer periphery of the base 24a of the cage 24. Furthermore, one axial end face of the outer ring 22a of the second ball bearing 22 is disposed opposite the inner surface 24e of the outer periphery of the base 24a, and each is positioned in the axial direction. In this way, each ball bearing 10, 22 is positioned in the axial direction by the base 24a of the single cage 24, and therefore no other positioning means is required, which reduces manufacturing and assembly costs.

[0109] Furthermore, by forming the axial width length of the inner surface 1e of the sprocket body 1a larger than the axial length of the outer ring 10b of the first ball bearing 10, it becomes possible to accommodate the use of an axially long sliding bearing in the second embodiment described below instead of the first ball bearing 10 as the bearing portion.

[0110] Furthermore, since the annular spacer 28 is arranged opposite the other axial end face of the outer ring 10b of the first ball bearing 10 via the internal gear component 5, it can cooperate with the inner surface 8f of the first annular regulating portion 8 to position the first ball bearing 10 in the rotational axis direction.

[0111] Moreover, when the engine is running, the lubricating oil in the reducer 13 is collected in the annular recess 26, which also functions as a temporary oil reservoir. This improves the lubrication between the internal teeth 5a and the roller 23 around the annular recess 26. Also, when the engine is stopped, a small amount of lubricating oil can be held in the annular recess 26, which improves the lubrication of the rolling bearings and the like when the engine is started.

[0112] Furthermore, since a portion of the annular recess 26 is located radially outward from the space between the bottom surface of the internal tooth 5a and the roller 23, contaminants such as metal powder generated from each component of the internal combustion engine and the reducer 13 can be accumulated in the annular recess 26 by the centrifugal force during driving.

[0113] Furthermore, six grooves 27 are provided on the outer periphery of the annular recess 26, and each of these grooves 27 functions as a pocket, so that a large amount of lubricating oil is stored in the annular recess 26. As the amount of lubricating oil stored increases, the lubrication of the second ball bearing 22 of the reducer 13 and the like is further improved. Also, it becomes possible to effectively store contaminants in each of the grooves 27 functioning as a pocket.

[0114] In addition, since centrifugal force acts on the lubricating oil during operation, the lubricating oil moves toward the outer periphery from each lubricating oil discharge hole 32 and is supplied to the bottom surface of each internal tooth 5a. Therefore, the lubrication between the bottom surface of each internal tooth 5a and the roller 23 is improved. Second Embodiment 10 and 11 show a second embodiment of the present invention, in which the first ball bearing 10, which is a rolling bearing in the first embodiment, is changed to a sliding bearing.

[0115] That is, as shown in Figures 10 and 11, the sliding bearing is composed of an annular bearing recess 40 formed on the inner surface of the sprocket body 1a, and a journal portion 41 provided on the outer periphery of the driven member 9 and positioned inside the bearing recess 40.

[0116] The bearing recess 40 has an annular bottom surface 40a, which is a bearing surface, that corresponds to the inner peripheral surface 1e of the sprocket body 1a of the first embodiment, and utilizes this inner peripheral surface 1e as is. The bearing recess 40 has one axial end on the camshaft 2 side covered by the first annular restricting portion 8, and the other end on the internal gear component 5 side open. This opening is closed by the axial abutment surface 5b of the internal gear component 5. As a result, the bearing recess 40 is formed on the entire inner peripheral surface of the sprocket body 1a, from the annular inner side surface 8f of the first annular restricting portion 8 to the bottom surface 6a of the annular recess 6. The bearing recess 40 is arranged so that a part of it axially overlaps with the formation position of each external tooth portion 1b, as shown in FIG. 1.

[0117] The bearing recess 40 has an annular bottom surface 40a which serves as a sliding bearing surface, and the annular inner side surface 8f of the first annular restricting portion 8 is formed at a substantially right angle in the radial direction from the bottom surface 40a of the sliding bearing surface.

[0118] The journal portion 41 protrudes from the outer peripheral edge of the disk-shaped main body 9a of the driven member 9 towards the front plate 15, and is formed in a rectangular cross-sectional shape that is nearly similar to the cross-sectional shape of the bearing recess 40. Since the bearing recess 40 overlaps with each of the external teeth portions 1b in the axial direction, the journal portion 41 is also disposed so that a portion of the journal portion 41 overlaps with each of the external teeth portions 1b in the axial direction.

[0119] A disk-shaped groove portion 9g surrounded by a journal portion 41 is formed on the inner end surface of the driven member 9 opposite the camshaft 2. The annular outer peripheral surface of the journal portion 41 is capable of sliding over the entire bottom surface 40a of the bearing recess 40. This allows the journal portion 41 to function as a plain bearing that supports the entire sprocket 1 via the bearing recess 40.

[0120] The journal portion 41 is disposed such that one end face 41a on the axial front plate 15 side faces the axial abutment surface 5b of the internal gear component 5 with a small gap C therebetween. The journal portion 41 is configured such that the axial abutment surface 5b restricts the entire driven member 9 from moving in the axial direction opposite to the camshaft 2. In other words, the axial abutment surface 5b functions as a restricting surface for the driven member 9.

[0121] Further, the other axial end face 41b of the journal portion 41 is slidable on the annular inner side face 8f of the first annular restricting portion 8. The annular inner side face 8f of the first annular restricting portion 8 is adapted to come into contact with the other end face 41b, which is the other end, when the sprocket 1 is tilted, thereby restricting the other thrust movement.

[0122] As in the first embodiment, an opening 11 is formed between an inner peripheral surface 8a of the first annular restricting portion 8 and an outer peripheral surface 19c of the second annular restricting portion 19.

[0123] A first recess 29 is formed on one side surface of the outer periphery of the disc-shaped main body 9a on the side of the first annular restricting portion 8. This first recess 29 is formed in a wide arc groove shape along the circumferential direction on one side surface on the radially outer side of the second annular restricting portion 19 of the disc-shaped main body 9a, and on two portions excluding the second stopper protrusions 19a, 19b. This first recess 29 faces the opening 11 in a communicating state, and its outer periphery extends to the other end surface 41b of the journal portion 41, and an inclined surface 29a is formed near the other end surface 41b.

[0124] Similarly to the first embodiment, the second recess 30 is formed by cutting out an inner edge of the inner peripheral surface 8a of the first annular restricting portion 8 in a circular shape along the circumferential direction, and is formed in a substantially arc-shaped cross section. The second recess 30 faces the opening 11 together with the first recess 29, and is open toward the inner peripheral side of the other end face 41b of the journal portion 41, and is disposed opposite the inclined surface 29a of the first recess 29.

[0125] Therefore, according to the second embodiment, by using a sliding bearing for the bearing portion, it is possible to reduce manufacturing costs and assembly costs compared to the first ball bearing 10 of the first embodiment.

[0126] Moreover, since the first recess 29 is formed widely on the outer surface of the outer periphery of the disc-shaped main body 9a facing the camshaft 2, the lubricating oil O collected at the opening 11 is well retained within the first recess 29, as shown in Fig. 11. As a result, the lubricating oil O is sufficiently supplied between the bearing recess 40 and the journal portion 41 by centrifugal force, improving the lubricating performance of these sliding bearings.

[0127] Furthermore, since the inclined surface 29a of the first recess 29 and the second recess 30 are arranged opposite each other, the lubricating oil O held in the first recess 29 can be actively supplied between the inner surface 8f of the first annular regulating portion 8 and the other end surface 41b of the journal portion 41 while being temporarily held between the inclined surface 29a and the second recess 30 via centrifugal force.

[0128] Furthermore, in this embodiment, the sprocket 1 provided in the first embodiment can be used as is, which reduces manufacturing costs.

[0129] The present invention is not limited to the configuration of the above embodiment, and the bearing portion may be, for example, a needle bearing as a rolling bearing. In addition, the reducer 13 may be a gear other than the roller 23. In other words, the reducer may be applied to a planetary gear reducer described in JP 2019-85910 A, for example, other than a roller reducer. [Explanation of symbols]

[0130] 1...timing sprocket (driving rotor), 1a...sprocket body (main member), 1b...external teeth portion, 1c...boss portion, 1d...female thread hole, 1e...inner peripheral surface (fixed surface), 2...camshaft, 2a...one end portion, 3...phase change mechanism, 4...oil supply passage, 4a...axial passage portion, 4b...radial passage portion, 5...internal gear component, 5a...internal teeth, 7...bolt, 7a...shaft portion, 7b...male thread portion, 8...first annular regulating portion (annular convex portion), 8a...inner peripheral surface, 8b·8c...arc-shaped groove portion, 8d·8e...first stopper convex portion, 9...driven member (driven rotor), 1 0...first ball bearing (bearing portion), 10a...inner ring, 10b...outer ring, 11...opening, 12...electric motor, 13...reduction gear, 19...second annular regulating portion, 19a...19b...second stopper convex portion (protrusion portion), 21...eccentric shaft member, 22...second ball bearing, 22a...outer ring, 22b...inner ring, 24...retainer, 24a...base, 24d...outer surface, 24e...inner surface, 28...annular spacer, 29...first recess, 30...second recess, 40...bearing recess, 40a...bottom surface (bearing surface), 41...journal portion, 41a...one end surface, 41b...other end surface.

Claims

1. a drive rotor to which rotational force from a crankshaft is transmitted; a driven rotor coupled to a camshaft and rotatable relative to the driving rotor, the driven rotor having a fixed portion to which an end of the camshaft is fixed and a disk portion provided radially outward of the fixed portion; a bearing portion provided between the disk portion and the driving rotor; an electric motor that rotates the driven rotor relative to the driving rotor; an opening provided between the driving rotor and the driven rotor and opening in the direction of the camshaft; a first annular recess that opens toward an inner periphery from the bearing portion of the driven rotor, the first annular recess having a radially outer surface of the disk portion facing the camshaft and facing the opening; A valve timing control device for an internal combustion engine comprising:

2. 2. The valve timing control device for an internal combustion engine according to claim 1, the driving rotor has an annular protrusion that protrudes radially inward at an end portion of the driving rotor that is on the camshaft side in the rotation axis direction and faces an outer periphery of the bearing portion, a second recessed portion provided on said annular protrusion on said bearing portion side in the direction of the rotation axis and facing said opening, said second recessed portion being configured to be in contact with said bearing portion and to be in contact with said opening.

3. 3. The valve timing control device for an internal combustion engine according to claim 2, The bearing portion is a first ball bearing disposed between the disk portion and the driving rotor, the first ball bearing is formed such that a width in the rotation axis direction is longer than a width in the disk portion, and both ends in the rotation axis direction protrude from both side surfaces of the disk portion in the rotation axis direction, 13. A valve timing control device for an internal combustion engine, wherein the first recess has an opening end on a radially outer side facing an outer peripheral surface of an inner ring of the first ball bearing, the inner ring protruding in the rotational axis direction.

4. 4. The valve timing control device for an internal combustion engine according to claim 3, a reducer disposed between the driving rotor and the driven rotor, the reducer comprising: an internal gear provided on an inner periphery of the driving rotor; an eccentric shaft member rotated by rotation of the electric motor; a second ball bearing disposed on an outer periphery of the eccentric shaft member; a plurality of rollers disposed between an outer periphery of the second ball bearing and the internal gear; and a cage fixed to the driven rotor, the cage having a plurality of retaining holes for retaining each of the rollers; the retainer has a base portion fixed to the driven rotor and an annular cage portion having a plurality of retaining holes that retain the plurality of rolling elements, 2. A valve timing control device for an internal combustion engine, wherein the base portion has a positioning portion that positions the first ball bearing and the second ball bearing in an axial direction.

5. 5. The valve timing control device for an internal combustion engine according to claim 4, 2. A valve timing control device for an internal combustion engine, wherein at least one of the side surfaces of the positioning portion where the first ball bearing and the second ball bearing abut in a sandwiched state is flat.

6. 6. A valve timing control device for an internal combustion engine according to claim 5, 2. A valve timing control device for an internal combustion engine, wherein the driven rotor has a protrusion on an outer periphery thereof for axially positioning the driven rotor and facing one axial end face of an inner ring of the first ball bearing.

7. 5. The valve timing control device for an internal combustion engine according to claim 4, a valve timing control device for an internal combustion engine, characterized in that the driving rotor has a fixed surface to which an outer ring of the first ball bearing is fixed, and the axial width of the fixed surface is formed larger than the axial width of the outer ring of the first ball bearing.

8. 8. A valve timing control device for an internal combustion engine according to claim 7, The driving rotor has a main member on which the fixed surface is formed and an internal gear component member on which the internal gear is formed, the main member being formed separately from the internal gear component member, a spacer provided integrally with the outer surface of the inner peripheral portion of the internal gear component, or provided between the internal gear component and the other axial end face of the outer ring of the first ball bearing, which restricts movement of the first ball bearing in the rotational axis direction.

9. 3. The valve timing control device for an internal combustion engine according to claim 2, The bearing portion is a sliding bearing having a journal portion provided on an outer periphery of the disk portion and a bearing surface formed on an inner circumferential surface of the driving rotor and sliding against the journal portion, 2. A valve timing control device for an internal combustion engine, wherein the first recess is formed in an outer surface of an outer periphery of the disc portion on the camshaft side and opens into the opening.

10. 10. The valve timing control device for an internal combustion engine according to claim 9, 13. A valve timing control device for an internal combustion engine, wherein a radially outer surface of the first recess expands toward the camshaft and directly communicates with the second recess.

Images